Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 16
·5498-5504
·
IF 6.4
Haoyu Xu,Xuanyang Guo,Hui Yang,Qing Zhou,Shiyan Liu,Haifeng Gao,Chao Gao,Wei Yu
In this study, Cu2ZnSn(S,Se)4 (CZTSSe) films were prepared by a non-vacuum solution method. The efficiency of an as-fabricated CZTSSe solar cell was improved from 8.0% to 10.9% by adding NaTFSI (sodium bis(trifluoromethanesulfonyl)imide) in the precursor solution. It was found that the NaTFSI additive could facilitate the formation and grain-growth of CZTSSe during the selenization of the film. As a result, the size of the crystalline grains in the CZTSSe films increased. Besides, a shallow level acceptor rather than a deep level acceptor could be generated in the CZTSSe films by using the NaTFSI additive. The use of NaTFSI could also decrease the relative content of the low valence Sn2+, which was believed to be related with deep level defects in CZTSSe. In addition, the effect of the NaTFSI concentration on the properties of CZTSSe solar cells were investigated. We found that excess NaTFSI in the precursor solution would not influence the recombination of the carriers in the neutral region of the solar cell, but could enhance the recombination of the carriers in the depletion region of the solar cell. Therefore, the performances of CZTSSe solar cells were reduced when excess NaTFSI was added in the precursor solution.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2023
·
IF 6.9
Lei Wang,Ruijian Liu,Hongmei Luan,Yiming Wang,Letu Siqin,Shuyu Li,Jiayong Zhang,Bin Yao,Chengjun Zhu
The absorbers of kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) that have undergone rapid thermal process (RTP) selenization typically exhibit a double-layer structure, with a fine crystal layer at the bottom, which degrades the performance of devices. We propose an efficient strategy for actively constructing the double-layer absorber to improve the quality of the small grains in the bottom layer. Compared to traditional methods, this method ensures uniform element distribution, particularly for Se element, and enables a more desirable Cu-poor and Zn-rich composition with a Zn/Sn ratio closer to the standard stoichiometric ratio, resulting in a reduction in harmful internal defects. This strategy eliminates small grains at the bottom and decreases grain boundary formation, resulting in a dense double-layer structure. The high-quality CZTSSe absorber not only reduces carrier recombination during back transmission, further reducing reverse saturation current (J 0 ) and increasing optical current density (J L ), but also enhances shunt resistance (R sh ) and decreases series resistance (R S ). The estimated contribution percent for PCE improvement due to changes in J L , J 0 , R sh , R S , and A are 17.20 %, 120.01 %, 1.15 %, 6.50 %, and -44.86 %, respectively. Ultimately, the highest photoelectric conversion efficiency (PCE) increased from 8.73 % to 10.49 %, and device uniformity improved considerably. This study highlights the significance of optimizing the microstructure of CZTSSe absorber layer in enhancing the performance of CZTSSe solar cells, and will provide guidance for producing high-quality CZTSSe absorber layers.
研究领域:
材料科学
·
太阳能技术
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2024
·
IF 6.3
Yunjie Bai,Yiming Wang,Ruijian Liu,Yu He,Yuhao Zhang,Chu Liu,Hongmei Luan,Yanchun Yang,Chengjun Zhu
The CZTSSe absorber layer prepared with DMSO exhibits extensive cavities at its bottom, and a prominent double-layer structure is frequently observed within the CZTSSe absorber synthesized using DMF , both of which have a detrimental impact on the device performance. In this paper, an alternate spin-coating process using DMSO and DMF solvent systems is proposed, which eliminates the double-layer structure of CZTSSe and reduces the number of cavities at the bottom of the absorber layer, thereby enhancing its overall quality. This method outperforms the traditional single-solution spin-coating technique by combining the advantages of two solvent systems, allowing for the preparation of an ideal CZTSSe film without disturbing the elemental ratio, ultimately resulting in a single-layer absorber composed of large grains. After three repetitions of an identical alternate spin-coating process, the average grain size of the absorber layer increased from 0.83 to 1.21 μm. This innovative process leads to a reduction in carrier recombination and an improvement in the short-circuit current density, ultimately raising the photoelectric conversion efficiency from 7.40% to 8.88%.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·Vol. 20
·期 50
·2405908
·
IF 13
Lei Wang,Letu SiQin,Yiming Wang,Shuyu Li,Wenjing Xin,Jingyuan Guo,Ruijian Liu,Hongmei Luan,Chengjun Zhu
The Sol-gel precursor solution reaction mechanism has a significant impact on the Cu 2 ZnSn(S, Se) 4 (CZTSSe) solar cells. It is discovered that in the Cu 2 ZnSnS 4 (CZTS) precursor solution (CZTS-PS) in the preparation, there is an association reaction among Cu 2+ , thiourea (Tu), and carboxyl (-COOH), which is an important reason for the undesirable CZTSSe solar cells. The strong association reaction generates excessive Cu 2+ ions, forming the Cu x Se secondary phase on the surface of the CZTSSe absorber. The secondary phase causes a short circuit and deterioration of gadget performance. Following a 6-h aging period for the CZTS-PS, the average photoelectric conversion efficiency (PCE) of the device is enhanced to 8.02%, and there is also an improvement in device uniformity, as evidenced by a decrease in the standard deviation to less than 1. To inhibit the association reaction and eliminate the aging time phenomenon, a strategy is developed using hydrochloric acid to regulate the CZTS-PS environment. This strategy shifts the REDOX reaction in Cu 2+ +Sn 2+ toward the formation of Cu 1+ +Sn 4+ , leading to a decrease in the defect concentrations of V Sn (−/0) and Cu Sn (−/0), which increases the carrier concentration and reduces the impact of band tailing. The average power conversion efficiency (PCE) of the devices improved from 7.45% to 9.26%, the PCE of the best-performing CZTSSe solar cells increased from 9.25% to 9.83%, and the consistency among the devices is further enhanced, as indicated by a reduction in the standard deviation from 0.98 to 0.44. Ultimately, the device performance of the Cu 2+ +Sn 2+ -DMF system improved by 11.01% (without the MgF 2 layer) after optimization. This study serves as a reference for regulating the environment of the CZTS-PS to further enhance the CZTSSe devices' performance, and the photoelectric conversion efficiency is improved by ≈30%.
研究领域:
材料科学
·
化学工程
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Chemistry
·
2019
·
IF 5.162
Biwen Duan,Linbao Guo,Qing Yu,Jiangjian Shi,Huijue Wu,Yanhong Luo,Dongmei Li,Sixin Wu,Zhi Zheng,Qingbo Meng
In CZTSSe solar cells, a simple sodium-incorporation post-treatment method toward solution-processed Cu 2 ZnSnS 4 precursor films is presented in this work. An ultrathin NaCl film is deposited on Cu 2 ZnSnS 4 precursor films by spin-coating NaCl solution. In subsequent selenization process, the introduction of NaCl is found to be benefacial for the formation of Cu 2- x Se, which can further facilitate the element transportation, leading to dense and smooth CZTSSe films with large grains and less impurity Cu 2 Sn(S,Se) 3 phase. SIMS depth profiles confirm the gradient distribution of the sodium element in Na-doped absorbers. Photoluminescence spectra show that the introduction of appropriate sodium into the absorber can inhibit the band tail states. As high as 11.18% of power conversion efficiency (PCE) is achieved for the device treated with 5 mg mL −1 NaCl solution, and an average efficiency of Na-doped devices is 10.71%, 13% higher than that of the control groups (9.45%). Besides, the depletion width and the charge recombination lifetime can also have regular variation with sodium treatment. This work offers an easy modification method for high-quality Na-doped CZTSSe films and high-performance devices, in the meantime, it can also help to further understand the effects of sodium in CZTSSe solar cells.
研究领域:
材料科学
·
太阳能电池技术
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2016
·
IF 4.732
Jing Guo,Wen-Hui Zhou,Ying-Li Pei,Qing-Wen Tian,Dong-Xing Kou,Zheng-Ji Zhou,Yue-Na Meng,Si-Xin Wu
CZTSSe based thin film solar cells have received considerable interests due to low material cost, suitable band gaps and high absorption coefficient of CZTSSe materials. Achieving high efficiency CZTSSe based thin film solar cells often need a high temperature selenization process that always causes Sn loss in the form of gaseous SnSe 2 . Additional Sn complement may decrease the loss of Sn during selenization process and improve the performance of fabricated CZTSSe based thin film solar cells. Here, we investigate the effect of additional Sn complement on the performance of CZTSSe based thin film solar cells fabricated from pure element solution. XRD and Raman characterizations indicate that additional Sn complement could reduce the secondary phase that may cause the voltage loss and decrease of efficiency. The solar cell fabricated with 15% additional Sn complement shows the best conversion efficiency of 8.71% (V OC =0.42 V, J SC =32.73 mA cm −2 , FF=63.19%). To the best of our knowledge, it is the highest efficiency of CZTSSe based thin film solar cells fabricated from pure element solution.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2022
·
IF 6.959
Fengxia Yang,Xiaofei Dong,Lei Yu,Xudong Sun,Jiangtao Chen,Yun Zhao,Yan Li
The cation ratio in Cu-poor and Zn-rich CZTSSe absorbers is key to decide the photovoltaic performance of CZTSSe solar cells, while its toleration and the influence mechanism is still not clear. In this work, for single-layer-structured CZTSSe absorbers spin-coated from metal chloride precursors with constant Cu and Zn values, the Zn/Sn ratio is regulated in the range of 0.8∼1.6. It is found that the Zn/Sn ratio has great influence on the morphology and electrical properties of the CZTSSe absorbers and thus the performance parameters of the CZTSSe cells. Comparatively, the results show that a 1.2 Zn/Sn ratio can boost the photovoltaic efficiency to 10.65% with a relatively high open-circuit voltage (VOC) of 481 mV and a reduced VOC-deficit of 585 mV. Detailed studies indicate that the 1.2 Zn/Sn ratio could favor the large-grain growth, increase the carrier concentration, suppress the carrier recombination, and reduce the band-tail effects and Urbach energy, thus leading to the highest efficiency with superior photovoltaic performance. The optimization of the Zn/Sn ratio in chloride precursor-coated CZTSSe absorbers would be beneficial for in-depth understanding of the effect mechanism of the element ratio on device performance.
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2021
·Vol. 33
·期 49
·2104330
·
IF 30.849
Yali Sun,Pengfei Qiu,Wei Yu,Jianjun Li,Hongling Guo,Li Wu,Hao Luo,Rutao Meng,Yi Zhang,Shengzhong (Frank) Liu
As a low-cost substitute that uses no expensive rare-earth elements for the high-efficiency Cu(In,Ga)(S,Se) 2 solar cell, the Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cell has borrowed optimization strategies used for its predecessor to improve its device performance, including a profiled band gap and surface inversion. Indeed, there have been few reports of constructing CZTSSe absorber layers with surface inversion to improve efficiency. Here, a strategy that designs the CZTSSe absorber to attain surface modification by using n-type Ag 2 ZnSnS 4 is demonstrated. It has been discovered that Ag plays two major roles in the kesterite thin film devices: surface inversion and front gradient distribution. It has not only an excellent carrier transport effect and reduced probability of electron-hole recombination but also results in increased carrier separation by increasing the width of the depletion region, leading to much improved V OC and J SC . Finally, a champion CZTSSe solar cell renders efficiency as high as 12.55%, one of the highest for its type, with the open-circuit voltage deficit reduced to as low as 0.306 V (63.2% Shockley-Queisser limit). The band engineering for surface modification of the absorber and high efficiency achieved here shine a new light on the future of the CZTSSe solar cell.
研究领域:
材料科学
·
光伏技术
·
半导体物理
·
表面工程
·
能源材料
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Chunkai Wang,Ting Wang,Yue Liu,Mengge Li,Ding Ma,Zhanhui Ding,Yan Zhu,Yuting Sun,Xiaofei Sun,Liyuan Shi,Ning Ding,Yongfeng Li,Bin Yao
To improve the performance of Cu2ZnSn(S,Se)4 solar cells, a strategy is proposed to improve the quality of absorber and back interface simultaneously by substituting V-doped Mo (Mo:V) for a conventional Mo back electrode and incorporating Ag into the Cu2ZnSn(S,Se)4 (ACZTSSe) absorber in this work. Since p+-type V-doped MoSe2 (MoSe2:V) is formed in the site between the absorber and Mo:V during selenization, the conventional Mo/n-MoSe2 back contact is modified to Mo:V/p+-MoSe2:V, a back surface passivation field (BSPF) is established at the back interface, the band bending of MoSe2:V is downward and that of bottom of the absorber is upward. Further investigation reveals that the back contact modification and Ag doping have a synergistic effect on inhibiting carrier recombination, decreasing series resistance and increasing shunt resistance, thereby leading to the PCE of device without antireflection coating increased from 8.61 to 10.98%, which is larger than the sum of increase in PCE induced by Ag doping alone (8.61 to 9.66%) and back contact modification alone (8.61 to 9.63%). It is demonstrated that the synergistic effect stems mainly from the strengthened BSPF and the further reduced back contact barrier height. The former is due to the increased difference in work function (WF) between MoSe2:V and absorber induced by the reduced WF of the absorber after Ag doping and the raised WF of MoSe2:V after V doping. The latter is due to the downshifted valence band maximum of absorber after Ag doping. This work highlights the synergistic effect of back contact modification and Ag doping on improving the performance of CZTSSe solar cells and also provides an effective way to suppress carrier recombination.
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2023
·
IF 6.9
Zhu Kou,Jinhui Wang,Xingrui Tong,Pengyang Lei,Yi Gao,Siyu Zhang,Xinpan Cui,Sixin Wu,Guofa Cai
Electrochromic smart windows provide an important route to reduce building energy consumption by dynamically adjusting the transmission of visible and near-infrared light. However, the requirement for an external electrical supply greatly limits their application in energy-saving buildings. Herein, we develop a novel photovoltaic (PV) cell-powered electrochromic energy storage smart window prototype by the combination of nickel-cobalt bimetal oxide electrochromic window and Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cell, which not only realizes the function integration of self-power and intelligent solar radiation regulation, but also extends its function to energy storage. Specifically, the obtained NiCoO 2 electrochromic films display a large optical modulation (60.0% at 550 nm), fast switching time (7.6/11.4 s), outstanding stability and excellent rate capability. Based on the achieved NiCoO 2 film and TiO 2 film, high-performance electrochromic energy storage smart windows (EESW) were further assembled and demonstrated excellent compatibility with CZTSSe solar cell. Benefiting from the unique merits of CZTSSe cell, the self-powered EESW exhibits excellent optical modulation (56.0% at 550 nm) and fast coloration speed (17 s). Moreover, the self-powered EESW can serve as a power source to drive external electronics. Our exploration of multi-functional smart windows offers an effective strategy to realize a highly efficient low-energy building in the future.
研究领域:
材料科学
·
能源技术
·
建筑节能
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2020
·Vol. 22
·期 11
·3597-3607
·
IF 9.48
Hai-Qin Xiao,Wen-Hui Zhou,Dong-Xing Kou,Zheng-Ji Zhou,Yue-Na Meng,Ya-Fang Qi,Sheng-Jie Yuan,Qing-Wen Tian,Si-Xin Wu
Cu2ZnSn(S,Se)4 (CZTSSe) solar cells have been receiving considerable attention in recent years, owing to their low cost and toxicity as well as a high abundance of their constituent elements. Solution-based (mainly precursor solution) methods have been widely used in the fabrication of CZTSSe-based thin film solar cells. Though most record solar cells since 2009 have been achieved using solution-based methods, carbonaceous residues are always formed during post deposition treatment (PDT). These carbonaceous residues are detrimental to grain growth of CZTSSe to form large grains. The presence of unwanted small grain layers will increase the series resistance and reduce the fill factor of the solar cell, thus consequently decreasing the efficiency of CZTSSe solar cells. Herein, we propose “green” supercritical carbon dioxide (SCCO2) treatment to overcome the challenge of carbonaceous residues. FT-IR, SEM, XRD and Raman characterization studies were used to confirm the reduction of carbonaceous residues in CZTSSe films. The solar cell fabricated from a selenized CZTSSe precursor film with SCCO2 treatment under optimal conditions showed the best conversion efficiency of 11.23% (VOC = 0.456 V, JSC = 36.6 mA cm−2, FF = 67.1%). To the best of our knowledge, this is the first report on boosting the efficiency of solution-based CZTSSe solar cells by using SCCO2 treatment. In addition, this unique SCCO2 treatment may also bring forth new ideas for other solution-based optoelectronic devices.
研究领域:
材料科学
·
太阳能
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Yu Mao,Yuanyuan Huang,Yanmei Deng,Mengyang Wang,Wenjian Chan,Ziyang Ren,Ening Gu,Xianzhong Lin,Guowei Yang
Inkjet-printed Cu 2 ZnSn(S,Se) 4 (CZTSSe) has emerged as a promising route for cost-effective and high-throughput production of photovoltaic devices. To further enhance the performance of CZTSSe solar cells, it is urgently necessary to address the issues of severe interface recombination and carrier transport resistance within the devices. In this sense, a surface modification strategy is introduced by treating the inkjet-printed CZTSSe absorber surface with cadmium chloride (CdCl 2 ). As a result, the Cd-treated CZTSSe films exhibit smooth and compact surfaces and a small conduction band offset, which boosts carrier transport. Furthermore, the Cd treatment significantly reduces interface defects from 5.1 × 10 15 to 2.4 × 10 15 cm −3 , thereby reducing carrier recombination while expanding the depletion width from 138 to 272 nm and improving carrier collection efficiency. Consequently, the optimized CZTSSe device achieves a stimulating increase in power conversion efficiency from 11.83% to 13.64%, which is the highest efficiency reported to date for inkjet-printed CZTSSe solar cells. This work provides critical insights for advancing cost-effective and high-performance inkjet-printed CZTSSe solar cells.
研究领域:
光伏技术
·
材料科学
·
半导体器件
·
薄膜技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）